Goofs: Laser scalpels cauterise as they cut? Either this has to be a specific setting or even minor surgery would be unnecessarily tricky.

Dialogue Triumphs: "How do you do?" "How do I do what?" "Do you know, I really don't know..."

"Hatred is irrational. It's a law unto itself."

"Principles cost. You can afford them if you've nothing left to lose."

Double Entendres: "We all did things we weren't proud of at the Academy."

Continuity: The Drashani Empire is a galaxy-spanning civilisation across which war between the Royal Houses of Gadarel and Sorsha has lasted decades.

Prince Kylo is the youngest son (the "runt of the litter") of the late king Aldon Sorcha and heir to the house of Sorcha.' His great-grandfather the 'mad' Emperor Lukor died apparently through his own pyrokinesis - a genetic abnormality in the family line which manifests in Kylo's own, untamed, pyrokinesis.

Princess Aleona is of House Gadarel; her father Valdan Gadarel was killed in battle a few months ago, and Aleona's imminent wedding to Kylo is assumed to represent a new hope for the Empire. Gadarel's ambassador Tuvold's daughter Cheni is cousin to Aleona and next in line to the Gadarel throne. Corwyn's wife was on the firebombed Morlitz V

Gadarel and Sorcha technology is quite different, by Aleona's recollection. Her gun latches onto specific DNA and kills what matches. DNA readers come as standard with medi-kits, but are basic, requiring separate sample to be put in a box for scanning.

The Royal Wedding vestments include the royal carcanet and the Ashfarn cloak.

The Igriss are eight foot tall bipedal killing machines with sabre teeth and deadly claws, ostensibly a slave race genetically modified and bred for mining work on the planet Sharnax, on which the Igriss population revolted forty years earlier. The royal carcanet's stones were from there.

The Doctor calls pyrokinesis a very specific form of telekinesis, acting on a molecular level. It is a recurrent mental genetic abnormality of the Drashani house.

The Doctor knows of the Drashani Empire only by repute and hasn't visited it before. He intends to return to Amsterdam to collect Nyssa and Tegan who are holidaying in the city (The Elite). Tegan and Nyssa are to meet the Doctor at Central Station.

The Doctor snaps at Tuvold, calling him 'Tegan' by mistake - he expects to be criticised by her, and explains this as a nervous reaction due to her not being around (but obviously in his thoughts.)

Links: This story takes place after Arc of Infinity and Omega, both of which are alluded to in this story; its events lead into The Acheron Pulse. The Doctor calls Tuvold "Tegan", referring to his supposedly being en route to return for her - "perhaps I should make it more of a round trip..."

John Dorney invokes the spirit of Caves of Androzani with crashing spaceships, doomed crew and a body count that almost hits the hundred per cent mark. Davison s great in this, given the chance to show his iteration of perhaps the most constantly frustrated incarnation of the Doctor, surrounded by dangerous fools and beset by monsters. That said, there's a lack of Robert Holmes' trademark humour in the story - it's a bit grim, and the final histrionics are not unexpected if you know you're listening to part one of a trilogy, but as openers go, it's a pretty sound one.